Aromatic oligomeric phosphate compositions which are not hydroxy-terminated are known to persons of ordinary skill in the art with representative examples being described in European Patent Publication Nos. 509,506 and 521,628 and Japanese Patent Publication No. 227,632/1988.
A hydroxy-terminated aromatic oligomeric phosphate is depicted as one of the products formed by the processes described in Japanese Patent Publication No. 223,158/1989. The product that is desired is a mixture of 22%-65%, by weight, of a reactive, hydroxy-terminated monophosphate ester, 15%-30% of a non-reactive, no-hydroxy-terminated phosphate ester, and 5%-63% Of the hydroxy-terminated oligomeric phosphate ester. This patent document teaches the use of such a mixture to flame retard phenolic resin.
Aromatic oligomeric phosphate compounds which are devoid of hydroxy termination are taught as flame retardants for polycarbonate resins in U.S. Pat. No. 5,204,394 to J.C. Gosens et al. Blends of tetra(lower alkaryl) p-phenylene diphosphate compounds and polycarbonate resin are disclosed in U.S. Pat. No. 5,122,556 to R.P. Kambour.
U.S. Pat. No. 4,463,130 to V. Serini et al. teaches flame-resistant polycarbonate resin-containing mixtures comprising a branched polyphosphate which can contain hydroxy functionality linked to the phosphorus atom of the phosphate moiety.
U.S. Pat. No. 5,278,212 to H. Nishihara et al. discloses the use of certain hydroxyphenyl-containing organophosphorus compounds as a flow modifier additive in thermoplastic resin compositions. The compounds represented by formula I at Col. 2, lines 35-45 of this patent contain only one hydroxy group when n is either 0 or 1 (see Col. 2, lines 57-58).